1. Field of the Invention
The present invention relates to a pattern recognition apparatus for recognizing a character pattern or a picture pattern (to be referred to as a pattern hereinafter).
2. Description of the Related Art
A conventional pattern recognition apparatus collates patterns obtained by learning in advance with a newly input pattern to recognize the input pattern.
For example, a character pattern is drawn by white dots and black dots, each white dot is represented by "0", and each black dot is represented by "1". In this case, if the dots are one-dimensionally developed, the character pattern can be represented by a vector consisting of "1" and "0" as follows.
Character pattern=[0, 0, 0, 1, 1, 0, . . . ]
The pattern recognition apparatus recognizes a specific vector space area to which the character pattern belongs on the basis of the vector of the character pattern, thereby classing the input character. A specific vector space area to which a specific character type belongs can be generally determined by a large number of on-the-spot character data.
Although the conventional pattern recognition described above has already been used in character recognition, recognition is performed depending on only information obtained by the input pattern. For this reason, if an input character is considerably deformed, and only incomplete information is obtained, the recognition method depending on only pattern matching has limitations in its recognition capability.
In contrast, man can recognize a character pattern having incomplete information because he/she imaginarily compensate the incomplete portion.
In addition, the above conventional method requires a very large number of pattern data for learning. For example, several thousand to several ten-thousand character patterns must be generally learned for character data, and a very long learning time is required. In contrast, man can also recognize a slightly deformed pattern by learning typical character patterns, and he/she does not learn several ten-thousand patterns. In this manner, the currently used pattern recognition apparatus performs only recognition which is more primitive than the recognition performed by man.